The article is aimed at assessing the possible negative impact of microclimate factors on work wellbeing, health and work productivity of the employees of the selected operation. In this paper, the effect of microclimate conditions such as air humidity, air flow and air temperature on workers comfort perception were studied. The research was carried out on a sample of 5 workers out of a total of 15 employees in the production hall. The aim of the research was to determine the level of influence of selected thermal parameters on the physical and mental well-being of employees. Participants were asked to complete a questionnaire designed to determine the level of perception of the impact of selected thermal parameters on the most vulnerable body parts. A mathematical model was used for a comprehensive assessment of the work environment's impact on employees. As the productivity of employees may also depend on employee satisfaction, research results can be used to improve the comfort of employees and to achieve better work performance.

In the research literature, the work environment is often characterized by physical, chemical, biological, and cultural complex factors that affect an employee at the workplace. The work environment is part of the "man-machineenvironment" system. In this system, "man" refers to the subject in the workplace (e.g operators, decision-makers), "machine" is the general name for any object controlled by man (tools, machines, computers), and "environment" describes the specific working conditions under which man and machine interact (temperature, noise, vibration, lighting, radiation, chemicals, hazardous gases etc.). The working environment creates a wider or narrower set of factors which are affecting this system. The role of this whole system is to create optimum conditions for achieving the desired results. The three main goals to optimize are to ensure safety, high efficiency, productivity and economy of "man-machineenvironment" system. Man-machine-environment system engineering is a new developing synthesis frontier science. It analyses three factors for man, machine and environment of the system and the relationship among them to make the system become "safety, and productivity. For problem-solving in this system, the physical factors are very important and may represent a significant risk for employees. These factors affect the human senses, burden the nervous system and can negatively affect overall health and cause stress. Factors can be external (from the environment, psychological, or social situations) or internal (illness). Examination and assessment of working conditions for their impact on employees are challenging, time-consuming and it is essential to do it regularly to achieve reliable results. This paper relates by comparing the results from previous and current assessments to capture developmental tendency, identify progress or regress and subsequently decide on the next steps.